1. Field of the Invention
The present invention relates generally to Global Positioning System (GPS) receivers, and in particular, to a two-bit offset canceling Analog-to-Digital (A/D) converter with improved common mode rejection and threshold sensitivity, typically used in GPS receivers.
2. Description of the Related Art
The use of GPS in consumer products has become commonplace. Hand-held devices used for mountaineering, automobile navigation systems, and GPS for use with cellular telephones are just a few examples of consumer products using GPS technology.
As GPS technology is being combined with these devices, the GPS chips are being placed in widely ranging applications. Some of these applications require that the GPS chip be made smaller, or more efficient, presenting challenges to GPS receiver chip designers. Many of the functions of GPS chips are now being pushed to the edges of performance capabilities.
One of these functions is the ability to separate a GPS signal from background noise. Noise is often interpreted as a component of the GPS signal, and, as such, creates problems with position determination and accuracy of the GPS functionality. As GPS chips are placed in lower signal strength environments, and GPS chips are designed to be placed in smaller and smaller devices, the ability of a GPS receiver to separate signal from noise becomes more important.
It can be seen, then, that there is a need in the art to provide GPS chips with increased ability to separate noise from desired GPS signals.